photo credit: tarsandsactionEnvironmental groups gathered on the National Mall in Washington, D.C. Sunday and marched on the White House for a climate change rally largely aimed at pressuring President Obama to reject the Keystone XL oil sands pipeline.

activists attended the rally, where speakers portrayed the battle over the pipeline as a struggle between grassroots green groups and deep-pocketed special interests.

“They’ve got the lobbyists. They’ve got the super-PACs. They made the campaign contributions. They’ve got this town in their pockets — they have got the situation under control. And then you show up. And then we show up. And we change the game,” Sen. Sheldon Whitehouse (D-R.I.) told the crowd not long before it marched on the White House.

Obama will decide whether the project goes forward because it crosses national boundaries. The pipeline would bring fossil fuels from Canadian tar sands fields to the Gulf Coast. Environmentalists are painting Obama’s upcoming decision as the litmus test for whether he plans to make good on recent comments about tackling climate change.

Activists at Sunday’s rally said approving the pipeline would taint Obama’s record on climate change. They said they hoped the demonstration would give the president the will to nix Keystone, even when a majority of both the House and the Senate want it built.